Last Thursday, an Air India employee died after being sucked into an engine on one of the carrier’s jets. On Sunday, an Air India plane made an emergency landing after the cockpit windscreen cracked. Then, on Tuesday, a bus collided with an Air India plane parked on the tarmac at the Kolkata airport.

The bus, ferrying a flight crew for another Indian carrier, Jet Airways, ran into an Air India ATR 42 and became jammed under one of its wings. No one was aboard the plane at the time, but one of its engines was damaged in the crash, an Air India spokesman said. Jet said no one on the bus was injured.

Questions about the ability of India’s civil-aviation regulators led the U.S. Federal Aviation Administration in January 2014 to downgrade India’s aviation-safety ranking and bar it from adding any flights to the U.S. In April, the rating was raised again.

Tuesday’s accident happened at about 5.30 a.m., according to the spokesman for Air India. The aircraft was scheduled to travel to Silchar, a city in the northeastern state of Assam, and neighboring Shillong, the capital city of the state of Meghalaya. The flights were cancelled on Tuesday.

Air India said that police in Kolkata and India’s civil aviation regulator were probing the incident. A government inquiry is also underway into the death of the member of Air India’s groundcrew, who was pulled into a jet engine as an Airbus A319 was pushing back from its gate at Mumbai’s airport.